I have had success with crushed up egg shells. I do this in the spring,
just as the hostas are starting to emerge from their winter sleep. I wash
the shells, then crush them in my hands and spread them in and around the
hostas. This has just about eliminated sluggies from eating holes in the
hosta leaves.

Another good thing is I don't have to do this every year, as the egg shells
seem to take quite a while to break down.

Dee